Ahead of state standardized testing, city schools will be extended an hour each day for a full week starting Monday, a move that has triggered a grievance from the teachers' union.

The school system has racked up at least six snow days this winter, with some students and teachers staying home an extra one to three days when 17 school buildings were closed because of snow and ice removal earlier this month.

The additional hour, through March 7, would make up one snow day and push the final bell at many schools past 4 p.m. The six extra instructional hours also come at a crucial time, school spokesman David Medina said Friday.

On March 8, students begin taking the Connecticut Mastery Test and Connecticut Academic Performance Test.

"That was the logic behind it ... to give extra time for the kids to prepare for the exams," Medina said. "It's a very involved process, just to reschedule the buses for that one week."

Andrea Johnson, president of the Hartford Federation of Teachers, said educators have been preparing students for the standardized tests since the start of the school year.

"It's going to cause a lot of difficulty for the children, for the teachers, for the principals, for the parents," Johnson said Friday. "For six hours? ... This is people's personal time after the school day, and the superintendent has failed to give that a thought."

The union filed its grievance Tuesday with Superintendent Steven Adamowski, who has 10 days from that date to respond. Adamowski could not be reached for comment Friday.

The R.J. Kinsella Magnet School of Performing Arts and the Greater Hartford Classical Magnet School, which already have extended day programs, are not subject to the scheduling change, Medina said.

By state law, public schools must be in session at least 180 days by July 1. The extra hours would bring the school system to its contractual 182 days. Currently, the last day of school in Hartford is scheduled for June 14, except for those schools with the one to three additional snow days.